Pressure operated subsurface well apparatus



M. B. CONRAD PRESSURE OPERATED SUB-SURFACE WELL APPARATUS Oct. 19, 1954 2 Sheeis-Sheet 1 Filed Sept. 26, 1949 INVENTOR.

flrroeuL-xs Mqerw B. Come/:0,

iii

Oct. 19, 1954 M. B. CQNRAD PBESSURE OPERATED SUBSURFACE WELL APPARATUS 2 Sheets-Sheet 2 Filed Sept. 26, 1949 MART/N A INVENTOR. B. Come/40,

Patented Oct. 19, 1954 UNITED STATES PATENT OFFICE PRESSURE OPERATED SUBSURFACE WELL APPARATUS Application September 26, 1949, Serial No. 117,877

(01. MiG-63) 18 Claims. 1

The present invention relates to well apparatus positionable in a well bore, and more particular ly to apparatus capable of utilizing a motivating fluid or gaseous force developed at the location of the apparatus in the well bore. In a more limited sense, the invention pertains to tools for running and setting well packers in well bores.

An object of the invention is generally to improve subsurface pressure developing devices for operating well equipment in well bores.

Another object of the invention is to provide an apparatus for developing a fluid or gaseous force in the well bore, for the purpose of perating well equipment therein, in which the appara tus can be made of a small diameter for the same effective total force produced, and also substantially shorter in length.

A further object of the invention is to provide an apparatus for developing a fluid force in a well bore, in which the effect of the hydrostatic head of fluid in the Well bore is counterbalanced, preferably completely, allowing all of the fluid force developed in the apparatus to be available for the operation of well equipment attached thereto.

Yet another object of the invention is to provide improved means for retarding the expansion of gas under pressure developed in subsurface well apparatus.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forrning part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such de tailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figs. 1 and 1a together constitute a longitudinal section through well equipment disposed in a well casing, Fig. la constituting a lower continuation of Fig. 1;

Fig. 2 is a view similar to Fig. 1a, illustrating the apparatus partially operated in the well casin Fig. 3 is a view similar to Fig. 1a, illustrating the apparatus more fully operated in the well casing;

Fig. 4 is a cross-section taken along the line 4-4 on Fig. 3;

Fig. 5 is a cross-section taken alon the line 5-5 on Fig. 3;

Fig. 6 is a cross-section taken along the line E6 on Fig. 1a;

Fig. 7 is a cross-section taken along the line !1 on Fig. 3.

The setting or operating tool A, disclosed in the drawings, is secured to the lower end of a wire line or cable B, which may have a central electrically conductive core C. The setting tool may be connected to a well packerD, that is to be set in packed-01f condition within a well casing E.

Although described in connection with the specific well packer illustrated in the drawings, it is to be understood that the setting or operating apparatus A can be used in conjunction with other specific well packers, and in the operation of other subsurface well equipment.

The well packer D includes an elongate central packer body In having a lower guide and abutment ll threaded, or otherwise attached, to its lower end, and an upper abutment l'2 movably mounted upon its upper portion. A lower, circumferentially continuous slip sleeve I3 rests upon the lower abutment ll and surrounds the upwardly projecting central boss [4 of the latter. This slip sleeve I3 is provided with an inner inclined surface [5 tapering upwardly and outwardly for cooperation with a companion tapered surface IS on a lower frusto-conical expander ll slidable along the body Ill.

A packing assembly l9, which is preferably of natural or synthetic rubber, encompasses the body and rests upon the upper end of the lower expander H.

The upper end of the packing sleeve l9 engages the lower end of an upper frusto-conical expander 26, which is also slidable along the upper portion of the packer body Ill, and has an up=- ward and inwardly tapering external surface 29 cooperable with a companion internal surface 30 on the interior of a circumferentially continuous upper slip sleeve 3| which engages the upper abutment [2. The inner end of the slip sleeve 3! encompasses a centering boss 32 depending from the upper abutment.

It will be noted from the drawings that the upper slip sleeve 3! and the upper expander 25 are substantially identical with the corresponding parts at the lower portion of the well packer. However, the parts are oppositely arranged. In addition, it is to be noted that the upper slip ring 3| is provided with upwardly facing wickers or teeth 33 for embedding in the wall of the well casing E, to prevent upward movement of the well packer D therewithin. The lower slip sleeve I3 is provided with downwardly facing wickers or teeth 34 for embedding in the casing abutment I 2.

wall, to prevent downward movement of the well packer therewithin.

The well packer D is set in the well casing B by moving the upper abutment E2 in a downward direction, and the body it and its lower abutment i l in an upward direction with respect to eachother. .Since the slipsleeves l3, 3i are initially circumferentially continuous, they are designed to break into segments upon imposition of a predetermined wedging force thereon.

Thus, each slip sleeve is of relatively thin section, and has inwardly extending longitudinal ribs 35 that cooperate with an associated expander ill or 26. Relative longitudinal .movement between each slip sleeve and its associated expander will cause the sleeve to be wedged over the expander and produce a fracturing. or.breaking;of each sleeve at its thin wall sections 35 into separate segments 31 (Fig. '7), such segments being movable along the tapered surface of the expander and outwardly into engagement'with the well casing E. Originally, the slips cannotexpand;in view of their circumferential continuity.

The well packer D is run in the-'well-casingto thedesired setting point, whereupon the upper abutment i2 is shifted downwardly of the body ill, to wedge the upper slip sleeve 31 (which is weaker than the lower slip sleeve !3) over the expander 25, producing fracture of the sleeve 3i into a plurality of segments 3? and their engagement with the well casing (Fig. 2). Inasmuch'as these slip segments 3'! are wedged between the upper expander 28 and the casing "E, they cannot move downwardly toany further extent. The packer body it is then shifted upwardly, causing its lower guideand abutment ll tomove upwardly, carrying the lower expander ii and lower slip ring IS with it as a unit. During this motion, the lower expander ll is movedtowardthe upper expander 26, shortening the packingsleeve I9 and expanding it'outwardly intofirm sealing engagement with the casing E (Fig. 3)

A continuation ofthe upward strain on the packer body it then wedges the lower slip sleeve I3 over the lowerexpan'der i'i, effecting fracture of the sleeve into a plurality of separate segments, of the same general character as the upper slip segments '31, and their longitudinal upward movement along the lower expander, accompanied by their radial outward shifting .into anchoring engagement with the well casing .B, such as disclosed in Fig. 3.

The well packer D is retained with its. .slipsand packing elements in their .ifully expanded positionsbya lockdevice provided between themovable upper abutment l2 and the'body it. This lock device takesthe. form .of an inherentlycontractible split sleeve 33 .of extended length. located within an inner. recess 39 .inthe movable .The sleeve is provided with upwardly facing annular teeth 48 on itsinterior engageable with the body ll), which mayhave a roughened exterior along'its upper portionto insure diggingin or biting of. theratchet teeth 45 with the body itself. The exteriorof the sleeve is provided with upwardly facing annular teeth M engageable with companion downwardlyfacing teeth 42..f.ormed..in the .movableabutment member.

As stated above,.the well packer Disiset by relative downward movement of the upper abutment l2 and upward. movementof the body it. Such .relative movements can occur without interference, since theinternal ratchet'teeth .49 on the lock sleeve 38.n1erely. ratchetoverthe. corresponding ratchet teeth or roughened surface 43 of the body, without any substantial resistance to its movement. However, any tendency for the body it) to move in a downward direction within 5 the upper abutment l2, or for the upper abutment to move in an upwarddirection with respect to the body, is prevented by thel'lockinglengagement of the internal teeth til of the sleeve 33 with -the roughened surface or teeth '33 of the body. "In efiect, the ring or sleeve 38 operates as a oneway coupling or clutch element, permitting relative upward movement of the body it but precluding its relative. downward movement; Any tendency forv the ring as to move downwardly with the body-and within the upper abutment I2, is resisted by wedging of the tapered faces of its *teeth MWlth the companion tapered faces formthe inclined surfaces of the buttress threads 32 in the movable abutment l2. Such wedging actionurges the ring tflinwardlyinto thelcody iewi'tha greater force.

.Asldescribed abovailthe. specific well. packer 'dis'olosedis set by. imposing adownwar'df'orce on thefiupper abutmentfl andan. upward .force on the body ii]. '.The setting toolA enablessuch forces tobeiimpartd to the :parts of thewell packer, to insure its .completeanchoringjn the well casing, .and automatic ..detachment l of the setting tool from .the wellpacker. after the. latter 3 has been fully set in the well casing The setting tool includes. an upper cylinder'lt in which. a. gradually increasing pressure. is .developed. This cylinder. includesan.upperskirt 5 i threadedly connected toahead 52, to which the wire line .B is attached in. leakprooffashion, in a known manner. The upper skirt @SI .isthreaded into a low r-cylinder skirt fitvthat has-a.- lower head .54 threadedly secured .to it. .Acupashaped.

skirt '53, and may initially. occupy-a position adjacent and.belowtheilowerend of the uppercskirt 5| (Fig. 1).. This piston has: piston. rings'i i, which may be in the form ofrubber or rubber-like 0 rings, disposed in ring grooves 5'1, the-,piston rings slidably and sealingly: engaging the wall of the cylinder skirt 53. .Leakage from the cylinder 5%] along theskirts 5!,53' may .be prevented by providing suitable seal rings 52 in grooves-55* within the upper-skirt-Mandthelower=head5 l The cup-shaped piston 55 .is .urgeddownwardly by generatin -agas underzgradually increasing pressure within a combustion chamber 69. formed may be a relatively slow burning combustiblefuel,

by one or more suitable side seals fi lengaging 70 the wall ofthe upper'skirti5 l' and carried within the barrel grooves 65. V

. Any suitable manner of. firing the. cartridge (52 may be employed. As disclosed speeilicallyin the drawings, the. cartridge-.may have. a. 'filamentrtii in an electric circuit with the conductivecore C piston v55 is 'slidable within the lower; cylinder engaging the inner wall of the lower cylinder skirt in theupper skirtifil. power'charge' 6,1,:which V i such as a railway fiareor fusee, is disposed inthe of the cable B. When the circuit through the filament is completed, it becomes incandescent and fires the powder in the cartridge 62, the flame being projected downwardly in the combustion chamber to and igniting the upper end of the power charge ti, which begins burning, to develop a gas within the combustion chamber at a gradually increasing pressure.

As the pressure increases in the combustion chamber, the piston 55 is urged downwardly. This downward movement is transmitted to a fluid medium in the upper cylinder 5% disposed below the piston. This medium may be predominately water 66 and an upper small layer of air 61, to allow for expansion and contraction of the water as a result of temperature changes before the cartridge 62 is fired. The water substantially completely fills the space in the upper cylinder 50 below the piston 55, and also extends downwardly through a passage 63 in the lower head, which passage is communicable with a central passage 6-52 provided in 2. depending rod l6, that is threadedly secured in the lower head. This rod extends through the upper head H of a lower cylinder l2 initially disposed adjacent the lower head 5 of the upper cylinder 50.

The lower cylinder 72 includes a cylinder sleeve is secured to and depending from the upper head it, and disposed along a composite piston 1 secured to an intermediate portion of the depending rod iii. Below the composite piston, the cylinder sleeve is is secured to a lower cylinder head '55 that has an external flange 16 clamped between the cylinder sleeve 13 and a depending skirt l? threadedly secured in the lower end of the sleeve 73. This skirt ll may rest upon the upper abutment I 2.

The upper and lower cylinder heads H, F5 are provided with suitable seal rings 18 engaging the inner wall of the sleeve '53 to prevent fluid leakage through the threaded portions of the latter. The upper and lower heads H, is are also slidable along the depending rod 19, leakage between the heads and rods being prevented by upper and lower seal rings l9 disposed in suitable ring grooves 38 in the heads and bearing against the periphery of the depending rod.

Initially, the lower cylinder head is disposed immediately below and adjacent the composite piston M. The lower head '15 preferably has an upwardly extending annular portion 8! engaging the piston it to provide a cylinder space 82 into which the water 56 may be forced from the passage E59 through the hollow rod 19. The water is forced through the rod passage and through a smaller passage or orifice 83, cominunicating with the cylinder space 82 through one or more radial ports 86, in order that the downward movement or the upper piston 55 will tend to force the liquid or water 66 down through the passages and ports 68, 69, 33, 84 into the cylinder space 82, urging the lower cylinder head it and the cylinder '52 in a downward direction. Conversely, the liquid under pressure acts upwardly over the area of the composite piston M, tending to shift the rod it and the upper cylinder 553 in an upward direction.

The composite piston 34 includes an upper portion 55 threaded into a lower portion 85. These two portions are secured to the rod it by forming V-shaped, circumferential ribs 87 in the periphery of the rod and securing a correspondingly ribbed two-part coupling ring 88 thereto. The coupling ring 83 is first mounted on the rod 10 and the upper piston portion 85 then slid over the rod until its threaded skirt a surrounds the coupling ring. Thereafter, the lower piston portion 86 may be moved upwardly from the lower end of the rod 18 to the coupling ring 88, and threaded onto the skirt portion 85a of the upper part. In this manner, the coupling ring 88 is secured between the upper and lower piston portions 85, 86 and to the rod l0, preventing longitudinal movement of the composite piston 14 with respect to the rod.

As has been stated, leakage between the rod is and lower cylinder head i5 is prevented by the side seal rings 79. In a similar manner, leakage between the composite piston 14 and the rod 10 m y ice-p v t d by the seal rings 96 in the upper and lower piston portions 85, 86- engaging the periphery of the rod. Leakage from the cylinder space t2 between the piston 14 and the cylinder skirt i3 is prevented by peripheral seal rings 9| disposed in ring grooves 92 and engaging the inner wall of the cylinder skirt.

In the original relative postitions or the parts, the upper head ll of the lower cylinder '12 is spaced substantially above the composite piston 14, whereas the lower head 75 of the cylinder is disposed adjacent the composite piston, but substantially above the upper abutment l2 and the upper end of the packer body it. The well fluid is permitted to enter the annular space 93 between the sleeve H and rod 19 below the lower head 15 through one or more vent ports 94 provided in the sleeve. However, the annular space as between the upper head 7! and composite piston i i and between the rod ill and cylinder skirt 73 is imperforate, to prevent well fluids from leaking thereinto. This space 95 originally may contain air at atmospheric pressure.

The dependin rod 18 is secured to the packer body l 9 through the agency of a disruptabl tension stud 9i whose opposite ends are threaded into the piston rod iii and the body Hi, respectively. The intermediate portion 98 of the tension stud is reduced in diameter to insure pulling apart of the stud at that point after the packer D has been fully set in the well casing E. When the rod "it is secured to the tension stud 9?, the sleeve ll is-engaging the upper abutment mem her I 2.

As described above, the well packer D is anchored in the well casing E by imposing a downward force on the upper abutment 12 member and an upward force on the packer body i0, causing the slips It, 3! and packing It to be expanded outwardly against the well casing. To provide this force, the cartridge 62 is fired to ignite the power charge 6!, which generates gas at a gradually increasing pressure. The pressure is exerted downwardly against the cup-shaped piston 55, which transmits the pressure force to the liquid 61, 6E therebelow, the liquid being forced through the central passage 68, 69, B3 in the lower head 54 and rod 10, and through the ports 84 into the cylinder space 82. This liquid under pressure exerts an upward force on the piston 14 secured to the rod Hi, and a downward force on the lower cylinder head 15, this downward force being transmitted throu h the sleeve it to the upper packer abutment l2.

As the pressure increases, the downward force on the upper abutment i 2 becomes sufiiciently great to break the upper slips 3i into segments and move them downwardly along the upper expander cone 26 and radially outward into anchoring engagement with the casing E (see Fig. 2). After this action has occurred, the wedged :upper eslips etend sto tprevent further downward -m'ovement ofr:the:-sleeve 'l'l azn'd theilower;cyl- :in'dersltZ connectedtthereto. Aszthe :pressuretin the .combustionchamber 26% continues .to...inicrease;thenpressure in'the cylinder space 82 also r-increases atithe same time,'urging the piston'l t and rod win an upwarddirection, and exerting --a;naupwarld .pullion the packer body It, through theitensionstud 91. This upward action'foreshortens and compresses the packing sleeve 59 -against the'casinglE, and then disrupts the lower slips:l3:into azplurality of segmentsand urges 1cm outwardly into anchoring engagement with the well casing (see-Fig.3)

the pressure continues to increase'to a'furth'er;=extent,ras a result of the continued combustion of the power charge 5!, the packer'parts are-urged more strongly against the casing, until 'thetensile strength of-the reduced diameter portionldfleofithe tensile stud- 9? is exceeded, which pulls the stud apart r at-= the .reduced diameter iportion' 9ii. andfrees' the setting tool A from the avail packerD. "The setting tool may then bereinove'd'from the well casing E.

'Dur-ingthedownward -=movement of the lower cylinder 12 along the piston "Hi androd iii, it is apparent-that the upper-head "H of the lower cylinder is moved downwardly away from the.

7 unit pressure developed inthe apparatus by the power charge 1 is relatively insignificant. Howeverythe lower cylinder head IE-need not oper ate against any pressure at all, during its downward movement, in view of the vent ports 9 provide'd through the depending sleeve,allowing any "fluid in sleeve below the head 75 to be exp lled through these vent ports.

The tool is also so designed as to avoid the "necessity for developing any pressure which serves no other purpose than to overcome the hydro "static head of fluidin the well casing. This hydrostatic head of fluid acts downwardly against the entire cross-sectional annular area B, of the upper head '5! of the lower cylinder. In view of the provision of the vent ports 94 in the sleeve Ti, this same hydrostatic head of fluid is acting upwardly over the entire combined annular cross-section area S of the lower head '55 and cylinder skirt Tl. to the area B. across the upper head ii. Since the hydrostatic head of-fluid' isacting over equal areas and in opposite directions, its effect is counterbalanced or nullified. This enables all of the pressure developed in the setting tool A to be utilized for the purpose or" setting the well packer D securely in the well casing E, and of disrupting'the stud fi'ifto'release the setting toolfrom "the set and anchored'packer.

'Ihe factthat all of-the fluid pressure is utilized in the settingof the packer allows the annular area of the piston'i l, and of the lower cylinder head iSf-Over"which the fluid pressure is acting, to be made smaller, as compared with devices in which the hydrostatic head of fluid int'he well casingmust-be overcome. Theme of smaller areas enables the. external diameter of the setting tool A to bemade smaller, thereby allowing the :setting tool :to be 'usediin well casings of smaller"diameterandalso allows'a'single This entire area S is equal per abutment l2. 'fluidtl, 56 can' be forced through "the orifiee83 and-into the cylinder space82. fluid, which issubstantially'entirelya liquid, is employed to prevent sudden expansion of'the gases in'the combustion'chamber 68 when the 'setting tool to ber-employed'f'in connectionswith the wetting of :a large number :of T sizes :of =-we11 packers l D, or other well; equipment.

'-The area of the'fioating .piston'55 may betmade greater than the internal area of the annular head itiexposedto'the liquid 66 1 inithezcylinder space 32.

Where this relationship existsgthe cylinder i2 will be'moved downwardly. aigreater "distancethan the:floating piston. Thus, the

lesser movement .of the floating piston :aenables the upper cylinders!) to be made-shorter,"-which correspondingly reduces .the' length of f the-f entire setting tool.

Therelationship of the'variousparts, by which the lower cylinder 72 is moved downwardly and the piston M and rod W are moved upwardlyalso *allows the entire setting tool A to be madeshorter than heretofore, since the cylinder 12 acts as -both a cylinder and a setting sleeve engaging the up- Moreover, the intermediate This intervening tension stud 9'! is released. Release ofthetensicnstud relieves the setting tool Aof its'load.

The ability of the water 66 to be transferred; 'freely between the upper and lower cylinders 50,

between the upper and lower cylinders, sinceit must be forced through theirelatively' smallvorifree 83 andports 84, which .greatly retard passage of the water into the lower cylinder space 82, and, as a result, retard movement of thevparts, especially'afterzthe tension stud 9'! has been disrupted.

.It is, accordingly, a parent that a settingor operating tool for well equipment has .beenprovided which need not buck or oiTsetIthe hydrostatic'head of fluidinthe well casing, which can ideviceto operate the same andincluding a sleeve slidable along. said piston insealing engagement therewith andalso having upper and lower inwardlydirected annular memberssecured to; said sleeveon opposite sides of said piston, said memj bers being. slidable along said. rod in sealingengagement. therewith; means for feeding fluid underrpressure through saidrod toa space within said. cylindersbetween' said piston and said lower annular member to shift said cylinder down wardlyrelative to said piston androdto-operate the well device; means for:entrapping fluidhetween saidpiston andsaid upperannular member; vthe annular .crossrseetional area of :said

membersvb eing equal andthe external transverse surface. otsaid upper annularmember.beingexposed .to the hydrostatic head of fluid withinithe well bore.

" 2. Inan operating apparatus for "well devlcesr a first cylinder; a rod secured to said first cylinder; a piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and including a sleeve slidable along said piston in sealing engagement therewith and having inwardly directed upper and lower annular members secured to said sleeve on opposite sides of said piston which are slidable along said rod in sealing engagement therewith; means providing a fluid under pressure within said first cylinder; and means for feeding said fluid to a space within said second cylinder between said piston and one of said annular members to shift said second cylinder relative to said rod and first cylinder to operate the well device.

3. In an operating apparatus for well devices to be located in well bores: a first cylinder; a rod secured to said first cylinder; a piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and including a sleeve slidabl along said piston in sealing engagement therewith and having inwardly directed upper and lower annular members secured to said sleeve on opposite sides of said piston, said members being slidable along said rod in sealing engagement therewith; means providing a fluid under pressure within said first cylinder; means for feeding said fluid to a space within said second cylinder between said piston and said lower annular member to shift said second cylinder downwardly relative to said rod and first cylinder to operate the well device; means for entrapping fluid between said piston and the upper annular member; the external cross-sectional areas of said members being substantially equal, and the external transverse surfaces of said members being exposed to the hydrostatic head of fluid within the well bore.

4. In an operating apparatus for well devices to be located in well bores; a first cylinder; a rod secured to said first cylinder; a piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and slidable along said piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said piston slidable along said rod in sealing engagement therewith; means for generating a gas under pressure in said first cylinder; and means for transmitting the force of such gas under pressure to a space within said second cylinder between said piston and one of said annular members to shift said second cylinder relative to said rod and first cylinder to operate the well device.

5. In an operating apparatus for well devices to be located in well bores: a, first cylinder; a rod secured to said first cylinder; a piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and slidable along said piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said piston slidable along said rod in sealing engagement therewith; means for generating a gas under pressure in said first cylinder; and means for transmitting the force of such gas under pressure to a space within said second cylinder between said piston and one of said annular members to shift said second cylinder relative to said rod and first cylinder to operate the Well device; the external crosssectional areas of said annular members being substantially equal, and the external transverse surfaces of said annular members being exposed to the hydrostatic head of fluid within the well bore.

6. In an operating apparatus for well devices: a first cylinder; a rod secured to said first cylinder; a first piston in said first cylinder; a second piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and slidable along said second piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said second piston slidable along said rod in sealing engagement therewith; means providing a motivating fluid in said first cylinder for action upon said first piston; and means including a fluid for transmitting the force imposed by said motivating fluid on said first piston into a space within said second cylinder between said second piston and one of said annular members to shift said second cylinder and operate the well device.

7. In an operating apparatus for well devices: a first cylinder; a rod secured to said first cylinder; a first piston in said first cylinder; a second piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and slidable along said second piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said second piston slidable along said rod in sealing engagement therewith; said rod having a passage therethrough providing communication between said first cylinder and a space within said second cylinder between said second piston and one of said annular members; means providing a motivating fluid in said first cylinder for action upon said first piston; and fluid means in said first cylinder and passage for transmitting the force imposed by said motivating fluid on said first piston to said second piston and said one of said annular members to shift said second cylinder and operate the well device.

8. In an operating apparatus for well devices: a first cylinder; a rod secured to said first cylinder; a first piston in said first cylinder; a sec-- ond piston secured to said rod; a second cylinder adapted to be operatively associated with the well device to operate the same and slidable along said second piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said second pistonslidable along said rod in sealing engagement therewith; said rod having a passage therethrough providing communication between said first cylinder and a space within said second cylinder between said second piston and one of said annular members; means providing a motivating fluid in said first cylinder for action upon said first piston; and fluid means in said first cylinder and passage for transmitting the force imposed by said motivating fluid on said first piston to said second piston and said one of said annular members to shift said second cylinder and operate the well device; the annular cross-sectional areas of said members being substantially equal, and the external transverse surfaces of said annular members being exposed to the hydrostatic head of fluid within the Well bore.

9. In an operating apparatus for well devices to be located in well bores: an upper cylinder; a rod secured to and depending from said upper cylinder; an upper piston in said cylinder; a lower piston securedto said rod; a lower cylinder sesame adapted to beoperatively associated with the well device to operate the, same and slidable along said lower piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said lower piston slidable along said rod in sealing engagement therewith; means providing .a motivating fluid in said upper cylinder above said upper piston for downward action upon said upper piston; and means including a fluid for transmitting the force imposed by said motivating fluid on said upper piston into a space within said lower cylinder between said lower piston and said lower annular member to shift said lower cylinder downwardly relative to said rod and upper cylinder to operate the well device.

10. In an operating apparatus for well devices to be located in well bores: an upper cylinder; a rod secured to and depending from said upper cylinder; an upper piston in said cylinder; a lower piston secured to said rod; a lower cylinder adapted to be operatively associated with the well device to operate the same .and slidable along said lower piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said lower piston slidable along said rod in sealing engagement therewith; means providing a motivating fluid in said upper cylinder above said upper piston for downward action upon said upp r piston; vmeans including a fluid for transmitting the force imposed by said motivating fluid on said upper piston into a space within said lower cylinder between said lower piston and said lower annular member to shift said lower cylinder downwardly relative to said rod and upper cylinder to operate the well device; and means for entrapping fluid betweensaid lower piston and upper annular member; the external annular cross-sectional areas of said members being substantially equal, and the external transverse surfaces of said annular members being exposed to the hydrostatic head of fluid within the well bore.

11. In an operating apparatus for well devices to be located in well bores: an upper cylinder; a rod secured to and depending from said upper cylinder; an upper piston in said upper cylinder; a lower piston secured to said rod; a lower cylinder adapted to be operatively associated with the well device to operate the same and slidable along said lower piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said lower piston slidable along said rod in sealing engagement therewith; said rod having a passage therein establishing communication between said upper cylinder and a space within said lower cylinder between said lower piston and said lower annular member; means providing a motivating fluid in said upper cylinder for downward action upon said upper piston; fluid means in said upper cylinder and passage for transmitting the force of said upper piston into said space between said lower piston and lower annular member to shift said lower cylinder to operate the well device; means for entrapping fluid between said lower piston and upper member; the external annular cross-sectional areas of said members being substantially equal; and the external transverse surfaces of said members being exposed to the hydrostatic head of fluid within the well bore.

12. In an operating apparatus for well devices to be located in well bores: an upper cylinder; a rod secured to and depending from said upper cylinder; an upper piston in said upper cylinder;

a lower piston secured to said rod; a lower cylinder adapted to be operatively associated with the well device to operate the same and slidable along said lower piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said lower piston slidable along said rod in sealing engagement therewith; said rod having a passage therein establishing communication between said upper cylinder and a space within said lower cylinder between said lower piston and said lower annular member; means providing a motivating fluid in said upper cylinder for downward action upon said upper piston; and fluid means in said upper cylinder and passage for transmitting the force imposed by said motivating fluid on said upperpiston into said space between said lower piston and lower annular member to shift said lower cylinderand operate the well device.

13. In an operating apparatus for well devices to be located in well bores; an upper -cy1inder;.-a rod secured to and depending from said upper cylinder; an upper piston in said upp cylinder; at lower piston secured to said rod; a lower cylinder adapted to be operatively associated with the well device to operate the same and slidable along said lower piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said lower piston slidable along said rod in sealing engagement therewith; said rod having a passage therein establishing communication between said upper cylinder and a space within said lower cylinder between said lower piston and said lower annular member, means providing a motivating fluid in said upper cylinder for downward action upon said upper piston; fluid means in said upper cylinder, passage and space within said lower cylinder for transmitting the force imposed by said motivating fluid on said upper piston into said space between said lower piston and lower annular member to shift said lower cylinder and operate the well device; and means providing an orifice in said passage.

14. In mechanism of the character described: a well device to be operated in a well bore; an apparatus operatively connected to said device to operate the same, said apparatus including a cylinder having longitudinally spaced annular members, piston means slidable relatively along said cylinder in sealing engagement therewith and with said annular members between said memhere, means for feeding fluid under pressure into said cylinder between said piston means and one of said members to shift said cylinder and operate the well device, means for entrapping fluid in said cylinder between said piston means and the other member, the annular cross-sectional areas of said members being equal.

15. In mechanism of the character described: a well device to be operated in a well bore; an apparatus operatively connected to said well device to operate the same, said apparatus including a longitudinally extending rod, a piston secured to said rod, a cylinder slidable along said piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said piston slidable along said rod in sealing engagement therewith, means for feeding fluid under pressure through said rod to a space within said cylinder between said piston and one of said. members to shift said cylinder to operate said well device, means for entrapping fluid between said piston and the other member,

the annular cross-sectional areas of said members being equal, and the external transverse surface of said other annular member being exposed to the hydrostatic head of fluid within the well bore.

16. In mechanism of the character described: a well device to be operated in a well bore; a first cylinder; a rod secured to said first cylinder and well device; a piston secured to said rod; a second cylinder slidable along said piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said piston slidable along said rod in sealing engagement therewith; means providing a motivating fluid under pressure within said first cylinder; means for feeding said fluid to a space within said second cylinder between said piston and said lower annular member to shift said second cylinder downwardly relative to said rod and first cylinder to operate said well device; means for entrapping fluid between said piston and the upper annular member; the external cross-sectional areas of said members being substantially equal, and the external transverse surfaces of said members being exposed to the hydrostatic head of fluid within the well bore.

17. In mechanism of the character described: a body; normally retracted means on said body adapted to be expanded laterally; a first cylinder; a rod secured to said first cylinder and body; a piston secured to said rod; a second cylinder slidable along said piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said piston slidable along said rod in sealing engagement therewith; means providing a motivating fluid under pressure within said first cylinder; means for feeding said fluid to a space within said second cylinder betwen said piston and said lower annular member to shift said cylinder downwardly relative to said rod and first cylinder to expand said normally retracted means laterally; means for entrapping fluid between said piston and the upper annular member; the external cross-sectional areas of said members being substantially equal, and the external transverse surfaces of said members being exposed to the hydrostatic head of fluid within the well bore.

18. In mechanism of the character described: a well device to be operated in a well bore; an apparatus operatively connected to said device to operate the same, said apparatus including a first cylinder, a rod secured to said first cylinder and well device, a piston secured to said rod, a second cylinder slidable along said piston in sealing engagement therewith and having upper and lower annular members on opposite sides of said piston slidable along said rod in sealing engagement therewith, means for generating a gas under pressure in said first cylinder, and means for transmitting the force of such gas under pressure to a space within said second cylinder between said piston and one of said annular members to shift said second cylinder relative to said rod and first cylinder to operate said well device, the external cross-sectional areas of said annular members being substantially equal, and the external transverse surfaces of said annular members being exposed to the hydrostatic head of fluid within the well bore.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,076,466 Thomas Oct. 21, 1913 1,364,865 Capell Jan. 11, 1921 1,482,256 Prall Jan. 29, 1924 1,630,810 Simpson May 31, 1927 2,016,394 Sikorsky Oct. 8, 1935 2,193,736 Onions Mar. 12, 1940 2,259,020 Wineman Oct. 14, 1941 2,266,382 Quintrell et al. Dec. 16, 1941 2,326,404 Spangler Aug. 10, 1943 2,370,942 Dick Mar. 6, 1945 2,373,006 Baker Apr. 3, 1945 

